We use LP gas for a few of our appliances and I have noticed that the pans ,while cooking, are getting a lot of soot on them. Recently I eliminated the LP tank for my barn/shop and tapped into the house line and ran it to the barn. This is the only change.Thoughts??

Usually that means a feed adjustment is needed on the burners themselves. On our propane cooktop there is an adjustment screw that i remember adjusting on each burner when I installed it. my guess is the line pressure changed a little when you connected the barn so the original burner set point needs to be tweaked. are you getting any yellow flame on the burners or is it a nice consistent blue?

yellow flames indicate less than optimal mix at the burner. is this a pilot style or ignition style burner? older pilot light style stove at the church would get yellow flames on pilot lights if deposits build up around the orifice.

step 1...double and triple check the fittings you recently put in with soapy water, look for bubbles. it's not a bad idea to check other fittings on the line even if you didn't recently mess with them.

step 2...check for deposits, dirt or clogs at the burners fouling the holes. maybe messing with the lines jarred some gunk loose.

step 3...if the above two check out and you still have a yellowish flame then tweak the adjustment screw on the burner to get back to a nice blue flame.